Study of ac conductivity mechanism and impedance spectroscopy in CNT-added Cu5Se75Te10In10 chalcogenide system

This study is devoted to the investigation of electrical properties of multi-walled carbon nanotube (MWCNT)-contaminated Cu-Se-Te-In chalcogenide glassy composite in the temperature range 303–373 K and frequency interval from 1 Hz to 1 MHz. The MWCNT/chalcogenide glass was characterized by means of X-ray diffractometer, field emission scanning electron microscope, impedance spectroscopy and electrical measurements. Electrical conductivity was increased by 10–100 times of magnitude by adding 1 and 2 wt% of MWCNT to it, changing the behaviour from insulator to the semiconductor. This rapid change in the electrical conductivity for carbon nanotube-added glasses is due to the highly conducting behaviour of carbon nanotubes. The data observed from dc conductivity measurement in the temperature range 303–373 K suggest that thermally activated hopping is the dominant conduction mechanism between localized states in band tails, which is explained by Mott’s model. The temperature-dependent relaxation phenomenon has also been examined by a detailed analysis of impedance spectra.